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« Four Letters Re: Advanced Medical Training and Facilities for Retreat Groups |Main| Wars, and Rumors of War »

Saturday May 10 2008

Letter Re: Advice on Stocking Up on Batteries

Sir;

I was wondering: How many batteries should I store for all my radios, flashlights, smoke detectors, and so forth? I'm also planning to get night vision goggles, soon. I assume rechargeables, right? If so, what kind [of rechargeables], and who has the best prices? - T.E. in Memphis.

JWR Replies: I recommend buying mainly nickel metal hydride (NiMH) batteries. Stock up plenty of them, including some extras for barter and charity. Unlike the older Nickel Cadmium (NiCd) technology, NiMHs do not have a "memory" effect. (The diminished capacity because of the memory effect has always been one of the greatest drawbacks to NiCds batteries.) The best of the breed are the latest Low Self Discharge (LSD) variants, such as the Sanyo Eneloop.

One discount supplier with a very good selection that I can enthusiastically recommend is All-Battery.com. They also have great prices on "throw away" batteries, such a lithium CR-123s.

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Thursday February 7 2008

From the SurvivalBlog Archives: Start With a "List of Lists"

Start your retreat stocking effort by first composing a List of Lists, then draft prioritized lists for each subject, on separate sheets of paper. (Or in a spreadsheet if you are a techno-nerd like me. Just be sure to print out a hard copy for use when the power grid goes down!) It is important to tailor your lists to suit your particular geography, climate, and population density as well as your peculiar needs and likes/dislikes. Someone setting up a retreat in a coastal area is likely to have a far different list than someone living in the Rockies.

As I often mention in my lectures and radio interviews, a great way to create truly commonsense preparedness lists is to take a three-day weekend TEOTWAWKI Weekend Experiment” with your family. When you come home from work on Friday evening, turn off your main circuit breaker, turn off your gas main (or propane tank), and shut your main water valve (or turn off your well pump.) Spend that weekend in primitive conditions. Practice using only your storage food, preparing it on a wood stove (or camping stove.)

A “TEOTWAWKI Weekend Experiment” will surprise you. Things that you take for granted will suddenly become labor intensive. False assumptions will be shattered. Your family will grow closer and more confident. Most importantly, some of the most thorough lists that you will ever make will be those written by candlelight.

Your List of Lists should include: (Sorry that this post is in outline form, but it would take a full length book to discus all of the following in great detail)

Water List
Food Storage List
Food Preparation List
Personal List
First Aid /Minor Surgery List
Nuke Defense List
Biological Warfare Defense List
Gardening List
Hygiene List/Sanitation List
Hunting/Fishing/Trapping List
Power/Lighting/Batteries List
Fuels List
Firefighting List
Tactical Living List
Security-General
Security-Firearms
Communications/Monitoring List
Tools List
Sundries List
Survival Bookshelf List
Barter and Charity List

JWR’s Specific Recommendations For Developing Your Lists:

Water List
House downspout conversion sheet metal work and barrels. (BTW, this is another good reason to upgrade your retreat to a fireproof metal roof.)
Drawing water from open sources. Buy extra containers. Don’t buy big barrels, since five gallon food grade buckets are the largest size that most people can handle without back strain.
For transporting water if and when gas is too precious to waste, buy a couple of heavy duty two wheel garden carts--convert the wheels to foam filled "no flats" tires. (BTW, you will find lots of other uses for those carts around your retreat, such as hauling hay, firewood, manure, fertilizer, et cetera.)
Treating water. Buy plain Clorox hypochlorite bleach. A little goes a long way. Buy some extra half-gallon bottles for barter and charity. If you can afford it, buy a “Big Berky” British Berkefeld ceramic water filter. (Available from Ready Made Resources and several other Internet vendors. Even if you have pure spring water at your retreat, you never know where you may end up, and a good filter could be a lifesaver.)

Food Storage List
See my post tomorrow which will be devoted to food storage. Also see the recent letter from David in Israel on this subject.

Food Preparation List
Having more people under your roof will necessitate having an oversize skillet and a huge stew pot. BTW, you will want to buy several huge kettles, because odds are you will have to heat water on your wood stove for bathing, dish washing, and clothes washing. You will also need even more kettles, barrels, and 5 or 6 gallon PVC buckets--for water hauling, rendering, soap making, and dying. They will also make great barter or charity items. (To quote my mentor Dr. Gary North: “Nails: buy a barrel of them. Barrels: Buy a barrel of them!”)
Don’t overlook skinning knives, gut-buckets, gambrels, and meat saws.

Personal List
(Make a separate personal list for each family member and individual expected to arrive at your retreat.)
Spare glasses.
Prescription and nonprescription medications.
Birth control.
Keep dentistry up to date.
Any elective surgery that you've been postponing
Work off that gut.
Stay in shape.
Back strength and health—particularly important, given the heavy manual tasks required for self-sufficiency.
Educate yourself on survival topics, and practice them. For example, even if you don’t presently live at your retreat, you should plant a vegetable garden every year. It is better to learn through experience and make mistakes now, when the loss of crop is an annoyance rather than a crucial event.
“Comfort” items to help get through high stress times. (Books, games, CDs, chocolates, etc.)

First Aid /Minor Surgery List
When tailoring this list, consider your neighborhood going for many months without power, extensive use of open flames, and sentries standing picket shifts exposed in the elements. Then consider axes, chainsaws and tractors being wielded by newbies, and a greater likelihood of gunshot wounds. With all of this, add the possibility of no access to doctors or high tech medical diagnostic equipment. Put a strong emphasis on burn treatment first aid supplies. Don’t overlook do-it-yourself dentistry! (Oil of cloves, temporary filling kit, extraction tools, et cetera.) Buy a full minor surgery outfit (inexpensive Pakistani stainless steel instruments), even if you don’t know how to use them all yet. You may have to learn, or you will have the opportunity to put them in the hands of someone experienced who needs them.) This is going to be a big list!

Chem/Nuke Defense List
Dosimeter and rate meter, and charger, radiac meter (hand held Geiger counter), rolls of sheet plastic (for isolating airflow to air filter inlets and for covering window frames in the event that windows are broken due to blast effects), duct tape, HEPA filters (ands spares) for your shelter. Potassium iodate (KI) tablets to prevent thyroid damage.(See my recent post on that subject.) Outdoor shower rig for just outside your shelter entrance.

Biological Warfare Defense List
Disinfectants
Hand Sanitizer
Sneeze masks
Colloidal silver generator and spare supplies (distilled water and .999 fine silver rod.)
Natural antibiotics (Echinacea, Tea Tree oil, …)

Gardening List
One important item for your gardening list is the construction of a very tall deer-proof and rabbit-proof fence. Under current circumstances, a raid by deer on your garden is probably just an inconvenience. After the balloon goes up, it could mean the difference between eating well, and starvation.
Top Soil/Amendments/Fertilizers.
Tools+ spares for barter/charity
Long-term storage non hybrid (open pollinated) seed. (Non-hybrid “heirloom” seed assortments tailors to different climate zones are available from The Ark Institute
Herbs: Get started with medicinal herbs such as aloe vera (for burns), echinacea (purple cone flower), valerian, et cetera.

Hygiene/Sanitation List
Sacks of powdered lime for the outhouse. Buy plenty!
TP in quantity (Stores well if kept dry and away from vermin and it is lightweight, but it is very bulky. This is a good item to store in the attic. See my novel about stocking up on used phone books for use as TP.
Soap in quantity (hand soap, dish soap, laundry soap, cleansers, etc.)
Bottled lye for soap making.
Ladies’ supplies.
Toothpaste (or powder).
Floss.
Fluoride rinse. (Unless you have health objections to the use of fluoride.)
Sunscreen.
Livestock List:
Hoof rasp, hoof nippers, hoof pick, horse brushes, hand sheep shears, styptic, carding combs, goat milking stand, teat dip, udder wash, Bag Balm, elastrator and bands, SWOT fly repellent, nail clippers (various sizes), Copper-tox, leads, leashes, collars, halters, hay hooks, hay fork, manure shovel, feed buckets, bulk grain and C-O-B sweet feed (store in galvanized trash cans with tight fitting lids to keep the mice out), various tack and saddles, tack repair tools, et cetera. If your region has selenium deficient soil (ask your local Agricultural extension office) then be sure to get selenium-fortified salt blocks rather than plain white salt blocks--at least for those that you are going to set aside strictly for your livestock.

Hunting/Fishing/Trapping List
“Buckshot” Bruce Hemming has produced an excellent series of videos on trapping and making improvised traps. (He also sells traps and scents at very reasonable prices.)
Night vision gear, spares, maintenance, and battery charging
Salt. Post-TEOTWAWKI, don’t “go hunting.” That would be a waste of effort. Have the game come to you. Buy 20 or more salt blocks. They will also make very valuable barter items.
Sell your fly fishing gear (all but perhaps a few flies) and buy practical spin casting equipment.
Extra tackle may be useful for barter, but probably only in a very long term Crunch.
Buy some frog gigs if you have bullfrogs in your area. Buy some crawfish traps if you have crawfish in your area.
Learn how to rig trot lines and make fish traps for non-labor intensive fishing WTSHTF.

Power/Lighting/Batteries List
One proviso: In the event of a “grid down” situation, if you are the only family in the area with power, it could turn your house into a “come loot me” beacon at night. At the same time, your house lighting will ruin the night vision of your LP/OP pickets. Make plans and buy materials in advance for making blackout screens or fully opaque curtains for your windows.
When possible, buy nickel metal hydride batteries. (Unlike the older nickel cadmium technology, these have no adverse charge level “memory” effect.)
If your home has propane appliances, get a “tri-fuel” generator--with a carburetor that is selectable between gasoline, propane, and natural gas. If you heat your home with home heating oil, then get a diesel-burning generator. (And plan on getting at least one diesel burning pickup and/or tractor). In a pinch, you can run your diesel generator and diesel vehicles on home heating oil.
Kerosene lamps; plenty of extra wicks, mantles, and chimneys. (These will also make great barter items.)
Greater detail on do-it-yourself power will be included in my forthcoming blog posts.

Fuels List
Buy the biggest propane, home heating oil, gas, or diesel tanks that your local ordinances permit and that you can afford. Always keep them at least two-thirds full. For privacy concerns, ballistic impact concerns, and fire concerns, underground tanks are best if you local water table allows it. In any case, do not buy an aboveground fuel tank that would visible from any public road or navigable waterway. Buy plenty of extra fuel for barter. Don’t overlook buying plenty of kerosene. (For barter, you will want some in one or two gallon cans.) Stock up on firewood or coal. (See my previous blog posts.) Get the best quality chainsaw you can afford. I prefer Stihls and Husqavarnas. If you can afford it, buy two of the same model. Buy extra chains, critical spare parts, and plenty of two-cycle oil. (Two-cycle oil will be great for barter!) Get a pair of Kevlar chainsaw safety chaps. They are expensive but they might save yourself a trip to the emergency room. Always wear gloves, goggles, and ear-muffs. Wear a logger’s helmet when felling. Have someone who is well experienced teach you how to re-sharpen chains. BTW, don’t cut up your wood into rounds near any rocks or you will destroy a chain in a hurry.

Firefighting List
Now that you have all of those flammables on hand (see the previous list) and the prospect of looters shooting tracer ammo or throwing Molotov cocktails at your house, think in terms of fire fighting from start to finish without the aid of a fire department. Even without looters to consider, you should be ready for uncontrolled brush or residential fires, as well as the greater fire risk associated with greenhorns who have just arrived at your retreat working with wood stoves and kerosene lamps!
Upgrade your retreat with a fireproof metal roof.
2” water line from your gravity-fed storage tank (to provide large water volume for firefighting)
Fire fighting rig with an adjustable stream/mist head.
Smoke and CO detectors.

Tactical Living List
Adjust your wardrobe buying toward sturdy earth-tone clothing. (Frequent your local thrift store and buy extras for retreat newcomers, charity, and barter.)
Dyes. Stock up on some boxes of green and brown cloth dye. Buy some extra for barter. With dye, you can turn most light colored clothes into semi-tactical clothing on short notice.
Two-inch wide burlap strip material in green and brown. This burlap is available in large spools from Gun Parts Corp. Even if you don’t have time now, stock up so that you can make camouflage ghillie suits post-TEOTWAWKI.
Save those wine corks! (Burned cork makes quick and cheap face camouflage.)
Cold weather and foul weather gear—buy plenty, since you will be doing more outdoor chores, hunting, and standing guard duty.
Don’t overlook ponchos and gaiters.
Mosquito repellent.
Synthetic double-bag (modular) sleeping bags for each person at the retreat, plus a couple of spares. The Wiggy’s brand Flexible Temperature Range Sleep System (FTRSS) made by Wiggy's of Grand Junction, Colorado is highly recommended.
Night vision gear + IR floodlights for your retreat house
Subdued flashlights and penlights.
Noise, light, and litter discipline. (More on this in future posts--or perhaps a reader would like to send a brief article on this subject)
Security-General: Locks, intrusion detection/alarm systems, exterior obstacles (fences, gates, 5/8” diameter (or larger) locking road cables, rosebush plantings, “decorative” ponds (moats), ballistic protection (personal and residential), anti-vehicular ditches/berms, anti-vehicular concrete “planter boxes”, razor wire, etc.)
Starlight electronic light amplification scopes are critical tools for retreat security.
A Starlight scope (or goggles, or a monocular) literally amplifies low ambient light by up to 100,000 times, turning nighttime darkness into daylight--albeit a green and fuzzy view. Starlight light amplification technology was first developed during the Vietnam War. Late issue Third Generation (also called or “Third Gen” or “Gen 3”) starlight scopes can cost up to $3,500 each. Rebuilt first gen (early 1970s technology scopes can often be had for as little as $500. Russian-made monoculars (with lousy optics) can be had for under $100. One Russian model that uses a piezoelectric generator instead of batteries is the best of this low-cost breed. These are best used as backups (in case your expensive American made scopes fail. They should not be purchased for use as your primary night vision devices unless you are on a very restrictive budget. (They are better than nothing.) Buy the best starlight scopes, goggles, and monoculars you can afford. They may be life-savers! If you can afford to buy only one, make it a weapon sight such as an AN/PVS-4, with a Gen 2 (or better) tube. Make sure to specify that that the tube is new or “low hours”, has a high “line pair” count, and minimal scintillation. It is important to buy your Starlight gear from a reputable dealer. The market is crowded with rip-off artists and scammers. One dealer that I trust, is Al Glanze (spoken “Glan-zee”) who runs STANO Components, Inc. in Silver City, Nevada. Note: In a subsequent blog posts I will discuss the relationship and implications to IR illuminators and tritium sights.
Range cards and sector sketches.
If you live in the boonies, piece together nine of the USGS 15-minute maps, with your retreat property on the center map. Mount that map on an oversize map board. Draw in the property lines and owner names of all of your surrounding neighbor’s parcels (in pencil) in at least a five mile radius. (Get boundary line and current owner name info from your County Recorder’s office.) Study and memorize both the terrain and the neighbors’ names. Make a phone number/e-mail list that corresponds to all of the names marked on the map, plus city and county office contact numbers for quick reference and tack it up right next to the map board. Cover the whole map sheet with a sheet of heavy-duty acetate, so you can mark it up just like a military commander’s map board. (This may sound a bit “over the top”, but remember, you are planning for the worst case. It will also help you get to know your neighbors: When you are introduced by name to one of them when in town, you will be able to say, “Oh, don’t you live about two miles up the road between the Jones place and the Smith’s ranch?” They will be impressed, and you will seem like an instant “old timer.”

Security-Firearms List
Guns, ammunition, web gear, eye and ear protection, cleaning equipment, carrying cases, scopes, magazines, spare parts, gunsmithing tools, targets and target frames, et cetera. Each rifle and pistol should have at least six top quality (original military contract or original manufacturer) full capacity spare magazines. Note: Considerable detail on firearms and optics selection, training, use, and logistic support are covered in the SurvivalBlog archives and FAQs.

Communications/Monitoring List
When selecting radios buy only models that will run on 12 volt DC power or rechargeable nickel metal hydride battery packs (that can be recharged from your retreat’s 12 VDC power system without having to use an inverter.)
As a secondary purchasing goal, buy spare radios of each type if you can afford them. Keep your spares in sealed metal boxes to protect them from EMP.
If you live in a far inland region, I recommend buying two or more 12 VDC marine band radios. These frequencies will probably not be monitored in your region, leaving you an essentially private band to use. (But never assume that any two-way radio communications are secure!)
Note: More detail on survival communications gear selection, training, use, security/cryptography measures, antennas, EMP protection, and logistical support will be covered in forthcoming blog posts.

Tools List
Gardening tools.
Auto mechanics tools.
Welding.
Bolt cutters--the indispensable “universal key.”
Woodworking tools.
Gunsmithing tools.
Emphasis on hand powered tools.
Hand or treadle powered grinding wheel.
Don’t forget to buy plenty of extra work gloves (in earth tone colors).
Sundries List:
Systematically list the things that you use on a regular basis, or that you might need if the local hardware store were to ever disappear: wire of various gauges, duct tape, reinforced strapping tape, chain, nails, nuts and bolts, weather stripping, abrasives, twine, white glue, cyanoacrylate glue, et cetera.

Book/Reference List
You should probably have nearly every book on my Bookshelf page. For some, you will want to have two or three copies, such as Carla Emery’s "Encyclopedia of Country Living". This is because these books are so valuable and indispensable that you won’t want to risk lending out your only copy.

Barter and Charity List
For your barter list, acquire primarily items that are durable, non-perishable, and either in small packages or that are easily divisible. Concentrate on the items that other people are likely to overlook or have in short supply. Some of my favorites are ammunition. [The late] Jeff Cooper referred to it as “ballistic wampum.” WTSHTF, ammo will be worth nearly its weight in silver. Store all of your ammo in military surplus ammo cans (with seals that are still soft) and it will store for decades. Stick to common calibers, get plenty of .22 LR (most high velocity hollow points) plus at least ten boxes of the local favorite deer hunting cartridge, even if you don’t own a rifle chambered for this cartridge. (Ask your local sporting goods shop about their top selling chamberings). Also buy at least ten boxes of the local police department’s standard pistol cartridge, again even if you don’t own a pistol chambered for this cartridge.
Ladies supplies.
Salt (Buy lots of cattle blocks and 1 pound canisters of iodized table salt.)
(Stores indefinitely if kept dry.)
Two cycle engine oil (for chain saw gas mixing. Gas may still be available after a collapse, but two-cycle oil will probably be like liquid gold!)
Gas stabilizer.
Diesel antibacterial additive.
50-pound sacks of lime (for outhouses).
1 oz. bottles of military rifle bore cleaner and Break Free (or similar) lubricant.
Waterproof dufflebags in earth tone colors (whitewater rafting "dry bags").
Thermal socks.
Semi-waterproof matches (from military rations.)
Military web gear (lots of folks will suddenly need pistol belts, holsters, magazine pouches, et cetera.)
Pre-1965 silver dimes.
1-gallon cans of kerosene.
Rolls of olive drab parachute cord.
Rolls of olive-drab duct tape.
Spools of monofilament fishing line.
Rolls of 10 mil "Visqueen", sheet plastic (for replacing windows, isolating airspaces for nuke scenarios, etc.)
I also respect the opinion of one gentleman with whom I've corresponded, who recommended the following:
Strike anywhere matches. (Dip the heads in paraffin to make them waterproof.)
Playing cards.
Cooking spices. (Do a web search for reasonably priced bulk spices.)
Rope & string.
Sewing supplies.
Candle wax and wicking.
Lastly, any supplies necessary for operating a home-based business. Some that you might consider are: leather crafting, small appliance repair, gun repair, locksmithing, et cetera. Every family should have at least one home-based business (preferably two!) that they can depend on in the event of an economic collapse.
Stock up on additional items to dispense to refugees as charity.
Note: See the Barter Faire chapter in my novel "Patriots" for lengthy lists of potential barter items.

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Saturday February 2 2008

AA Cells and Mobile Power, by Brandon in Utah

The size AA battery is the ubiquitous form of mobile power that is presently available. There is a large amount of off the shelf devices that use AA cells. They are available everywhere at low cost. They are cost effective and very safe for lighting. The breadth and depth of equipment available in a portable format is unparalleled by any other type of battery. I will cover the known factors on how to care for and use this resource to help end users get the most out of their equipment.

To start, some general information that covers all types of cells. Cells do not like heat. Heat increases the chemical reactions occurring inside the cell, and thus the self-discharge and other chemical reactions in cell. A cell will lose it's charge and lower it's life span. Keep them cool.

Cells shouldn't get wet. Keep them away from moisture. You should avoid circumstances that will result in condensation on the cell.
Do not drop or roughly handle them. Especially in the case of rechargeables, you can break the separator inside the cell and you may end up with complete cell failure. Inside of a device they're a little more durable, your device will provide some impact protection and buffering.

Do not store your batteries inside of your device for long term readiness. There is a good reason they never come this way from the manufacture in the package. It's not good for your battery and you run a much larger risk of cells leaking or venting into your device. On a short term basis in a device that sees regular use, leaving the battery in is fine.

Matched cells perform better. A battery will only perform as well as the weakest cell. Avoid mixing brands, dates, and especially chemistries and you will get the most out of your cells. The more cells a device has, the more matches cells you need to provide. So it's easier to feed devices that use a smaller number of cells.
In general, take care of them and they'll serve you well.

Primary (use once) cells are the most straight forward. They usually have expiration dates printed on the cell or package. It's important to note that this date is an average amount of time for a specified failure rate. "Fail" is defined as having less than ~85% capacity (depends on manufacture), thought it can also mean complete failure with 0% recoverable capacity. The closer a battery is to it's expiration date, the less capacity it will have and the more likely you are to encounter completely failed cells. Even with expired cells though, they often work. I wouldn't choose to use them in really important applications, but they are still useful.

"Heavy duty" cells generally are not worth messing with - they are cheap, light weight, and low capacity. They seem to only be made to sell to the "lowest possible price" consumers. I would never buy or store them.

Alkaline are the best bang for the buck primary cells. You can pick up a pack of 48 cells for around $10 at COSTCO last I checked (Duracell is believed to be the OEM for Kirkland brand cells). The price has gone up approximate 10-15% in the last year, which seems likely to continue. Alkaline's are good performers under "average" conditions. They do not like low temperatures, and they do not like high current draw (cameras, some flashlights, and possibly other devices). Once you place a battery into a device, I recommend you use it up. Do not return [primary] cells into storage once you've started to use them.

Lithium cells provide the widest temperature and current rating of all primary cells, though you pay the most for the best performance. I do recommend having a few for important gear, red dot sights, night vision,and so forth, [reserving them] especially for emergency winter use.

Rechargeable cells are much more economical for the regular user. Unfortunately they require better understanding to maximize their useful life. So I'll go over NiMH extensively and also address NiCd.
In a quick overview of the current tech of AA cells. NiCd is the most durable battery chemistry, it has capacities ranging from 600-1000 [mil-Amp Hours] (mAH) It has the best temperature performance envelope, endures heat and over charge best, will operate with more cycles. NiMH is the most common consumer cell these days, mostly due to the capacity advantage which run in the 1800-2700 mAH range at present. NiMH also has a new variant on the market I will dub low self discharge (LSD) cells. LSD cells are in the range of 2000-2100 mAH as of this writing and have many advantages over traditional NiMH that mostly come from an effort to stabilize it. They are new, so some data points are not borne out over years, but current evidence indicates that they perform as advertised. I recommend LSD cells for most people over all other varieties, I'll go into more detail why below. First, the brands and types currently on the market. The top brand in my opinion is Eneloops (2000 mAH) from Sanyo, it simply does the low-self-discharge thing better than the competition. The rest of the field seems to originate from a single manufacture or the same licensed design, but there are a bunch of competing cells. Rayovac Hybrids, Hybrios, Titanium Enduros, and a bunch of others (2100 mAH). Given equivalent, or near equivalent prices, I'd pick the eneloops.

In both types of chemistry, the higher capacity cells are more fragile than the lower capacity cells. It's an engineering trade off. The 2700 mAH whiz bang top-of-the-line cells are not your best bet for good durable cells, they are actually fairly fragile (chemically and physically) because of this trade off. Around 2000 mAH is not only cheaper (usually) but yields a cell that will see a longer service life, more cycles, and less likely to fail if dropped. Lower than 2000 in NiMH does not appear to hold significant advantage in durability in most respects. LSD cells appear to be at least as durable as their 2000 mAH NiMH counterparts.

Standard NiMH cells have an approximately life span of 3 years. Cheaper brands may have less. NiCd cells have an estimated 5+ year life span. Much beyond these points or even before them (especially with high capacity cells), increased internal resistance, lowered capacities, and higher self discharge are the norm. NiCd doesn't exhibit a large amount of this and usually fails with internal shorts (complete failure) or excessively high resistance. These numbers are very temperature dependant, colder storage conditions will lengthen the time, warmer will lower it. LSD NiMH cells currently have no data in this regard, they're advertised as having better longevity than NiMH cells, and I would tend to believe them due to the engineering trade offs picked. However, they've only been out for about 1.5-2 years now. To date, my oldest cells (1.5 years old), lightly used, perform like new - so far so good.

Self discharge is one of the biggest inconvenient things about rechargeable cell use. NiMH cells discharge by themselves very quickly. They discharge on the order of a couple of months when new and the rate increases significantly with age and use. NiCd cells have about half the self discharge rate and this usually won't vary much up until cell death. LSD cells shine in this regard, the self discharge slows down after a charge to almost a stand still in a little over a months time. LSD cells will retain around 85% (Eneloops) to 80% (rest of the field) charge after a year of storage at around 70 degrees.
Keeping the voltages up during use is important for many devices and one of the principle reasons rechargeables deliver poor performance in some devices. Standard NiMH suffers from voltage sag over time. It will start out at a nice high 1.4 volts fresh off the charger. Soon it finds it's way to 1.3-to-1.2 v open voltage. If left on the shelf it will fall over time. Many devices require a minimum voltage to operate correctly, if this minimum is above what your battery can deliver under load your device will shut down (can be 1.2v per cell, and NiMH will often fail to meet this under less than ideal circumstances!) If you experience significant performance difference between primary cells and rechargeable cells (especially older ones) this is likely the problem, especially combined with self discharge "usable capacity" drops very quickly. NiCd cells can suffer from a form of voltage sag, it is not as pronounced as NiMH but it can also happen in mid-discharge and is related the over marketed term cell "memory". This problem can usually be corrected with a couple exercise cycles and a good top off charge. LSD cells retain their voltage very well on the shelf, like their charge, and also deliver better than average voltages in normal use anyway. You will usually see much better performance from LSD cells in these voltage sensitive devices than NiMH or even NiCd. If you've been frustrated with rechargeables in the past in some of your devices give some LSD cells a try!

The most common method to kill cells is poor charging practices. I can't stress this enough, especially with NiMH cells, buy a good ["smart"] charger. Usually cells are allowed to "cook" on a standard charger for far, far too long. Remember, heat is bad! It's normal for them to get warm at the end of a charge cycle (not burning hot!). If they continue to stay warm (or worse, hot) for several hours later, you have a [traditional "dumb"] charger that is cooking your cells. I recommend a Maha-C9000 as a good high end charger. On a lower budget I recommend a Duracell 15 minute charger. {To be ready for various circumstances,] I prefer to have both chargers available. The C9000 is a slower charger (relatively) but it will not cook your cells, you can leave them in the unit. The unit has options that allow you to easily exercise cells and see if they are improving. You can match cells to obtain the best performance from them and identify poor performing cells quickly. It also charges individual cells rather than pairs, which is better for them - especially a mismatched pair. The Duracell 15 minute charger is a quality unit that also allows "busy you" to not walk away for hours waiting for, and forgetting about, your batteries. You will be less likely to forget about them and allow them to be cooked on the charger. Some good charging technology goes into the 15 minute chargers, so while they are a little rough compared to a good slower charge - they are actually very good at what they do, especially compared to the cheap junk [chargers] on the market. Fast charging is also fairly energy efficient, reducing the power required to get a full charge. Both of these chargers run on 12 volt DC input so they can plug directly into 12 volt systems allowing for use in a car or directly off a battery based [alternative energy] system (PV, wind, etc).

Do not charge cells when they are below freezing (32 F/0 C). You will damage them. If you really need a charged cell, warm it up in your pocket (preferably the charger too) and use the 15 minute charger. The charge cycle should provide enough heat to keep it above freezing until it's done. Avoid chargers that come with your cells, generally they are poor.

When brought out of long term storage, cells will usually need "exercise". NiCds especially need fairly significant exercise before returning to full capacity. 5+ full cycles may be required, rule of thumb is exercise until you stop seeing capacity gains. This is easiest with a charger like the C9000 with capacity readouts. NiCds should be stored discharged. NiMH cells should be stored with a charge. LSD cells require significantly less maintenance and may not need any exercise at all and will likely have a serviceable charge intact after storage, depending on the length of time in storage and at what temperature.
NiMH cells like to be treated gently. When you're done with your device, recharge the cells. The more shallow the cycle the better. Full cycles will wear on them the most. Keep NiMH cells topped off and they'll last the longest. Occasionally you may need to perform a deep cycle to restore some performance if the cell appears to be waning. The more advanced NiMH care systems like on the Toyota Prius reportedly keep cells at 60-80% capacity and only use about 20% depth in discharge cycles, which seems to be the most chemically repeatable and stable region. NiCds stand up to abuse a lot better, in fact a regular full discharge is good for them and will help you avoid issues with the cells. It's not required for every charge, but once a month or so should keep it's performance high.

I suggest avoiding C and D size rechargeable cells. They are expensive, there are no LSD variants at present, your charging options are more limited, they take forever to charge, and there are adapter sleeves readily available to make AA cells fit these sizes. D sized alkaline cells are reasonable for storage and use for the price. C size cells are usually overpriced and are often repackaged AA cells anyway - use the adapters. COSTCO presently sells an excellent Eneloop kit that includes 8 AAs, 4 AAAs, 2 AA->C adapters, 2 AA->D adapters, and a cheap charger for $26.

Earlier generation NiMH cells had a very poor temperature envelope. There are evidences that this has improved and the LSD introduction advertised even better cold temperature performance. Unfortunately, to date, I am unable to find information or a datasheet to quantify this. I've done a bit of my own testing down to 0 F, the limit of my freezer, and have found no appreciable drop in capacity (old NiMH tech struggled below freezing). I can't really quantify if LSD NiMH is inferior or superior to NiCds at present, so suffice it to say they both do reasonably well in the cold (just remember not to charge them when they are below freezing).

In summary, I don't see any reason to buy any non-LSD NiMH cells these days. LSD tech has dramatically improve the performance and user friendliness of the cells, and hopefully longevity, durability, and cycle life too. However, it is new and relatively unproven tech. NiCd is the old known workhorse and there is good reason why power tools and similar equipment still ship with NiCd cells. It's worth having a few NiCds around as a backup because of their track record. For general use, the Sanyo Eneloops are the way to go.

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Wednesday January 30 2008

Prepare or Die, by J. Britely

Throughout my life I have been caught unprepared several times and while nothing seriously bad happened, it easily could have.  I have been lost hiking.  My car has broken down in very bad neighborhoods - twice.  I have been close enough to riots that I feared they would spread to my neighborhood, been in earthquakes, been too close to wildfires, been stuck in a blizzard, and have been without power and water for several days after a hurricane.   I managed to get myself out of each situation, I thanked God, and tried to learn from my mistakes.  I could have avoided these situations or made them much less unsafe and worrisome if I had been more aware and prepared.  I have also tried to learn from the mistakes of others so as to not learn everything the hard way.  One group I assisted was a two hour drive into the mountains, out of gas, wearing tee shirts, and had empty water bottles (at least they kept them) (I have made each of those mistakes but not all at the same time).